FLIR Thermal Science Cameras Support Medical Research

Renowned US University uses FLIR cameras to study the effect of temperature on tissue autofluorescence.

Autofluorescence spectroscopy can be used for the purpose of surgical guidance, for example as an imaging technique for delineating surgical margins during cancer excisions (e.g. to be able to identify cancerous tissue close to the margin of normal tissue). As such, by studying autofluorescence, universities are trying to bridge the gap between fundamental science and their practical applications to healthcare.

Effect of temperature on autofluorescence

Despite its use in biomedical research, the relationship between autofluorescence and temperature in tissue has not been explicitly defined.

Many past studies have often assumed a constant temperature during measurements where in vivo experiments were assumed to be at body temperature and in vitro experiments were assumed to be at room temperature. However, there are instances in which the temperature may vary greatly such as during ablation surgeries. In these cases, an understanding of temperature effects on tissue autofluorescence is potentially crucial for accurate interpretation of results during these procedures.

In a series of preliminary experiments aided by the use of a FLIR A655sc thermal imaging camera, researchers from a renowned US university have shown an inverse relationship between temperature and autofluorescence for ex vivo human tissue.

Test set-up

A spectroscopy system equipped with a dual-excitation probe was used to measure the autofluorescence and diffuse reflectance of ex vivo human muscle tissue. Excitation light was provided by a 785 nm diode source while near-infrared autofluorescence emissions were collected by a charge coupled device (CCD) at a spectral resolution of 3.15 nm. The tissue’s temperature was continuously measured by a FLIR A655sc thermal imaging camera.

Ex vivo human muscle samples were acquired and stored at -80°C. During experiments, the samples were placed into a glass beaker and measurements were taken as the samples were allowed to passively warm up to room temperature. Once the sample reached 20°C, the sample was then submerged saline and gradually heated by a hotplate with measurements recorded at every 5°C increase in temperature.